There is known an asynchronous line-fed motor wherein the inductor is composed of individual laminated cores around which there is wound a concentrated multiphase winding. The cores form a row extending in the direction of travel of the magnetic field. The inductor is movable in relation to a secondary element having a current-carrying portion mounted on a magnetically conducting base (cf. U.K. Pat. No. 1,373,054, Cl. H2A).
The asynchronous line-fed motor under review has a low efficiency and develops a limited tractive effort.
There is also known an asynchronous line-fed motor (cf. French Pat. No. 1,592,065, Cl. H 02 K 41/04) comprising an inductor composed of individual laminated cores forming a row which extends in the direction of travel of the magnetic field. The cores have rods linked by a yoke. The rods have pole shoes at one of their ends. Coils of a concentrated multiphase winding are wound around the yokes which link the opposite ends of the rods. The inductor is movable in relation to a secondary current-carrying element of a current-carrying material which is shaped as a parallelepiped wherein the greater faces are symmetrically arranged between the pole shoes of the laminated cores.
The foregoing motor is objectionable because of a non-uniform distribution of the magnetizing force in the gaps between the pole shoes of the laminated cores of the inductor and the secondary element which is due to the serrated shape of the active zone of the inductor, i.e., of the inductor surface facing the secondary current-carrying element. The non-uniform distribution of the magnetizing force in this gap accounts for a low efficiency and limited tractive effort of the motor.